Container filling machine

ABSTRACT

A container filling machine provided with a plurality of filling heads having provision for automatically starting and stopping the filling operation in successive filling heads which includes pneumatically operated control means for each filling head for detecting a predetermined height of the material in its container and pneumatically operated means responsive thereto for discontinuing the filling operation, the invention being characterized by improved control means facilitating adjustment of the control units for the various filling heads to obtain uniform filling heights in successive containers.

United States Patent [56] References Cited UNITED STATES PATENTS 3,043,349 7/1962 Bennett 141/39 2,745,585 5/1956 Lindars 141/219X FOREIGN PATENTS 910,761 5/1954 Germany 251/28 Primary Examiner-Laverne D. Geiger Assistant Examiner-Edward J. Earls Attorney-Roberts, Cushman & Grover ABSTRACT: A container filling machine provided with a plurality of filling heads having provision for automatically starting and stopping the filling operation in successive filling heads which includes pneumatically operated control means for each filling head for detecting a predetermined height of the material in its container and pneumatically operated means responsive thereto for discontinuing the filling operation, the invention being characterized by improved control means facilitating adjustment of the control units for the various filling heads to obtain uniform filling heights in successive Patented May 25, 1971 12 Sheets-Sheet 1 I I I AL Iawezziow Wiiiiazn 1T. WlwseZZe, by 411 12 Q- -Uv. dim

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LO-PR NITROGEN 2 HFFR NITROG N 1 2 CONTAINER FILLING MACHINE This application is a continuation of application Ser. No. 550,391, filed on May 16, 1966, now abandoned.

This invention relates to a container filling machine of the gravity or pressure feed-type and comprises an improvement in the container filling machine illustrated and described in US. Pat. No. 3,182,691, issued May 11, 1965. The machine disclosed in the patent operates on a novel principle wherein air at low pressure is conducted through a nozzle into the container being filled during the bottle filling operation, and when the liquid level reaches a height in the bottle to block off escape of low pressure air through the end of the nozzle, a back pressure is built up to actuate pneumatically operated control means to effect closing of the liquid dispensing valve to discontinue the flow of liquid into the container.

In practice, it was found that in the operation of such prior machines the individual pneumatically operated control unit associated with each filling nozzle, while efficient in use, was difficult to adjust in order to cause successive filling units to operate in a manner such as to obtain uniform filling heights in successive containers.

Accordingly, it is one object of the invention to provide a novel and improved container filling machine having pneumatically operated control means of improved structure wherein the individual control unit associated with each filling nozzle may be easily and quickly adjusted in a manner such that successive filling units may be controlled to obtain uniform filling heights in successive containers.

Another object of the invention is to provide a novel and improved container filling machine having novel control means whereby the filling units for successive containers may all be adjusted simultaneously to change the filling heights uniformly in each container in a novel and efficient manner.

The invention has for another object to provide a novel and improved container filling machine provided with a novel structure of pneumatically operated control unit wherein provision is made for clearing the low pressure air nozzle of any accumulated material therein at the end of each filling operation in a simple and efficient manner.

A further object of the invention is to provide a novel and improved container filling machine of the character specified having novel provision for purging successive containers with an inert gas prior to and during the filling operation.

With these general objects in view and such others as may hereinafter appear, the invention consists in the container filling machine and in the various structures, arrangements, and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification.

In the drawings illustrating the preferred embodiment of the invention:

FIG. I is a vertical cross-sectional view of a container filling machine embodying the present invention;

FIG. 2 is a plan view of the machine shown in FIG. 1;

FIG. 3 is a detail view in side elevation and partly in cross section of a filling head and its associated pneumatic control unit;

FIG. 4 is a front elevation of the unit shown in FIG. 3;

FIG. 5 is a detail view in cross section of the pneumatic control unit shown in FIG. 3;

FIG. 6 is a cross-sectional view of a valve unit shown in FIG. 5 but at a larger scale;

FIG. 7 is a detail view in cross section of a portion of the valve unit shown in FIG. 6 as seen from the line 7-7 of FIG. 6;

FIG. 8 is an enlarged cross-sectional detail view of a low pressure air passageway adjacent the pressure sensing diaphragm as seen from the line 88 in FIG. 5;

FIG. 9 is an enlarged cross-sectional view of a portion of the control unit as seen from the line 9-9 of FIG. 5;

FIG. 10 is a front elevation ofthe control unit shown in FIG.

FIG. 11 is a schematic view of the air lines and the valve elements comprising the control unit shown in FIG. 5;

FIGS. 12, 13, I4, 15 and 16 are detail views of different types of filling head units adapted for use in the present machine;

FIG. 17 is a plan view detail of the cams for operating the pneumatically operated control unit;

FIG. 18 is a detail view of a cam shown in a different position for operating the control unit to effect clearing of the low pressure air nozzle;

FIG. 19 is an enlarged cross-sectional view of a portion of a modified form of a pneumatic control unit adapted for clearing successive low pressure air noules with pressurized inert gas;

FIG. 20 is an enlarged cross-sectional view taken on the line 20-20 ofFlG. 19;

FIG. 21 is a schematic view of the air lines and the valve elements comprising the modified control unit embodying provision for purging successive containers with an inert gas; and

FIG. 22 is a cross-sectional detail view of a modified form of central air distributing manifold for use when the containers are purged with an inert gas.

Referring now to the drawings, only those portions of the container filling machine which are necessary to an understanding of the present invention have been herein illustrated and described, reference being made to US. Pat. No. 3,182,69 l above referred to, for a more complete description thereof. In general, the present invention is embodied in a rotary bottle filling machine wherein a plurality of elevating platforms 12 are mounted to move in a circular path and to which successive bottles 14 to be filled are transferred by a transfer spider 13 from an intake conveyor 15, see FIG. 2. During continuous rotation in a circular path, the platforms 12 are arranged to be elevated to present the bottles in operative relation to their respective filling heads indicated generally at 16, the filling nozzles 18 thereof extending into the mouths of the bottles as shown. Upon completion of the filling operation the elevating platforms 12 are again lowered to a transfer level, and the filled bottles are transferred by a discharge spider 19 onto a discharge conveyor 21 to be delivered from the machine.

The filling head units 16 are carried by and rotatable with a rotary supporting disc 50, and each filling head unit has associated therewith a pneumatic control unit indicated generally at 52 supported above its filling head. Each control unit 52 is supported by an individual bracket 56 secured to and extended from the rotary supporting disc 50 as shown. Each control unit 52 includes a pneumatically operated cylinder 60 having a piston 62 arranged to cooperate with its filling head unit 16 to control the flow of liquid into the bottle. The filling head units 16 are arranged in circumferentially spaced relation and in vertical alignment with their respective elevating platforms l2 and the bottles 14 carried thereby. As shown in FIG. 3, each filling head unit comprises a hollow cylindrical nozzle block 22 providing a chamber 24 having an inlet 26 connected with a liquid supply conduit 28. Each nozzle block is supported by an extension 27 from its individual bracket 56 secured to the rotary supporting disc 50, the control unit 52 being supported at the upper end of the bracket as shown. The lower end of the nozzle block 22 is provided with a hollow tapering nozzle carrying portion 32 threadedly secured to the block and which forms a continuation of the chamber 24. The nozzle 18 is secured to or extended from the 7 lower end of the tapering portion 32. The upper end of the nozzle block 22 is provided 'with an adapter 34 threadedly secured thereto which forms a bearing for the stem 36 of a vertically movable liquid control valve 38. In the embodiment illustrated in FIG. 3, the valve 38 comprises a cylindrical member having an upstanding tubular portion and slidingly fitted in the lower end of the nozzle 18, the valve seat comprising an O-ring 40 carried by the cylindrical member. The valve stem 36 is provided with a relatively small diameter tubular extension or air nozzle 42 carried by an adapter 44 threadedly secured to the lower end of the stem, the lower end of the air nozzle 42 being secured to and extended through the valve 38.

The upper end of the air nozzle 42 communicates with a central passageway 46 formed in the valve stem 36, and the upper end of the passageway 46 is connected through a sidewall opening by a flexible conduit 48 to a source of low pressure air from the pneumatically operated control unit 52, as will be described.

A relatively heavy coil spring 49 interposed between the upper surface of the nozzle block 22 and a collar 53 carried by the stem 36 is arranged to urge the valve 38 upwardly into its closed position as shown. The stem 36 is also provided with a shouldered portion 54 which engages a shouldered portion formed in the nozzle block 22 to limit the upward movement of the valve. The lower end of the air nozzle 42 provides an outlet 58 open to the atmosphere. As illustrated, the small diameter air nozzle 42 extends into the liquid nozzle 18 providing an annular space therebetween. The valve 38 is closed at its lower end except for the air outlet 58, the sidewalls of the valve being provided with a plurality of liquid escape openings 59 as shown,

In operation, when the valve 38 is moved downwardly, it is telescopically extended from the lower end of the nozzle 18 to expose the openings 59 and permit the liquid to flow into the container. Conversely, when the valve 38 is moved upwardly to its closed position, the valve will be drawn upwardly within the nozzle 18, as shown, to close the liquid escape openings 59 and thus terminate the flow of liquid into the container.

The liquid supply conduit 28, as seen in FIG. 1, is radially extended from a central liquid distributing manifold 64 from whichsimilar conduits 28 extend to each filling head. The manifold 64 is mounted on and rotatable with the rotary supporting disc 50 on which the filling head units 16 are mounted. A central depending pipe 66 connected to and in communication with the manifold chamber is telescopically and rotatably received in a central stationary upstanding pipe68. The lower end of the pipe 68 is connected to an adapter 70, and a supply pipe 72 extends from the adapter to a supply tank 74. The liquid may flow from the tank by gravity to the distributing manifold and to the various filling heads, or the supply tank may be pressurized to effect a faster delivery of the liquid to the filling heads and into the bottles.

In operation, a continuous line of containers, such as bottles 14, on the intake conveyor are transferred onto successive platforms 12 by the transfer spider 13. During the continuous movement of the'platform in a rotary path, it is elevated to present the bottle into operative-filling position with its nozzle 18 extended into the mouth of the bottle. As the bottle is elevated, it engages a nozzle guide 76 which is provided with a flared opening arranged to receive the neck of the bottle to align it with its nozzle as shown in FIG. 4. The nozzle guide 76 'is carried by and detachably connected to a plate 78 supported on the ends of spaced slide rods 80 movable vertically in slide bearings 82. The slide bearings 82 are adjustably supported in the extension 27 in which the nozzle block 22 is also adjustably supported. The upper ends of the slide rods 80 are connected by a tie bar 86 which rests on top of the slide bearings 82 when the nozzle guide 76 is in its lowered position as shown. The nozzle guide is maintained in its lowered position by gravity, and in operation when the bottle is moved upwardly to engage the nozzle guide, the slide rods together with the tie bar 86 move upwardly. Conversely, when the platforms 12 are subsequently lowered, the nozzle guide and its slide rods are lowered, the tie bar 86 coming to rest on top of the slide bearings to limit the downward movement. In practice, a cam, not shown, cooperates with a roller 89 carried by the tie bar 86 to elevate the nozzle guide 22 at the end of the filling operation to release the containers for transfer to the discharge spider l9. Provision is made for preventing operation ofthe pneumatic control unit 52 in the event that no con tainer 14 is present on the platform 12 when it is elevated so as to prevent opening of the liquid control valve 38 at such time. As will be hereinafter described, the pneumatic control unit 52 is provided with pilot line 87, see FIG. 5, which is arranged to receive a momentary pulse of high pressure air to initiate the filling cycle. The pilot line 87 communicates with 21 normally closed air exhaust valve 88 carried by and secured to one side of the control unit 52 as shown in FIGS. 4 and 10. In operation, the normally closed air exhaust valve 88 is maintained in its open position until a container is elevated into operative filling position. The exhaust valve 88 comprises a housing provided with a chamber in communication with a conventional spring pressed tire valve, the stem of which extends into and elevates a button 90 above the housing when the valve is closed. The wall of the chamber has an exhaust opening 92 which is open to the atmosphere, and in operation, when the button 90 is depressed downwardly to open the tire valve, air from the pilot line 87 may pass through the valve into the chamber and out through the exhaust opening 92, thus rendering the pilot line 87 inoperative to activate the control unit 52. Conversely, when the button 90 is elevated by the tire valve stem to cut off the escape of air from the pilot line, the control circuit is rendered operative to activate the control unit.

As shown in FIG. 4, the tie bar 86 is provided with an upstanding rod 94 having a weight 96 slidingly mounted on the upper end thereof and which is arranged to engage and depress the button 90 to open the tire valve to permit escape of air through the exhaust port 92 when the nozzle guide 76 is in its lowered position. A weight elevating member comprising an elongated sleeve 98 is adjustably secured to the upstanding rod 94, and in operation, the upper end of the sleeve 98 is arranged to engage and lift the weight off the button 90 when a container is elevated into filling position. Thus, the button is spring pressed upwardly to permit closing of the tire valve. As a result, the pilot line is sealed so that when high pressure air is admitted to the pilot line 87 by a momentary pulse of air, the control unit is in readiness to initiate a filling cycle as will be hereinafter more fully described. Conversely, if no container is present, the weight 96 will not be lifted, and the tire valve will remain open to exhaust the pilot line through the opening 92, thus rendering the control unit 52 inoperative to start the filling cycle. Thus, in operation, if no container is present, the control unit 52 will not be activated to open the liquid control valve 38.

Referring now to FIG. 5, the pneumatically operated control unit 52 comprises, in general, a metal block 102 having bored portions therein for receiving the various control valves and having passageways therein for connecting selected control elements. The passageways include a high pressure air line or circuit 104 having an inlet 106 connected by a flexible conduit 108 to a source of high pressure air; a low pressure air line or circuit 118 having an inlet 112 connected by a flexible conduit 114 to a source of low pressure air; and the pilot line 87 arranged to be energized by a momentary pulse of high pressure air from the line 104 to initiate the filling operation at a time when a bottle is elevated into filling position to effect closing of the valve 88.

In general, and as also diagrammatically illustrated in FIG. 11, the control valves include a two-way normally closed trip valve 116 arranged to be opened by a stationary cam 118 during operation of the machine to admit a momentary pulse of high pressure air into the pilot line 87; a three-way normally closed pilot valve 120 in communication with the pilot line 87 and arranged to be opened when the pilot line 87 is energized by a momentary pulse of high pressure air, the valve 120 also having provision for maintaining the pilot line energized to hold the valve 120 open to high pressure air during the filling operation, Opening of the pilot valve 120 admits high pressure air from the line 104 through the valve 120 and through passageways I22, 124 to the cylinder 60 to extend its piston 62 which serves to depress the valve stem 36 of the filling head to start the filling operation.

As more specifically illustrated in FIG. 6, the pilot valve 120 comprises a middle or intermediate chamber 203 and end chambers 198 and 199 at opposite ends thereof formed in a core piece 103 recessed into the block 102, and a valve element 120a supported in the chambers. At the ends of the middle chamber 203 where they enter the end chambers there are conical valve seats. The valve element 120a has heads 200 and 202 situated in the end chambers and a stem 204 connecting them which extends through the intermediate chamber and is supported for longitudinal movement on the one hand to engage one valve head with its seat and disengage the other from its seat, and on the other hand to disengage the one valve head from its seat and engage the other valve head with its seat. Such longitudinal movement is afforded by flexible diaphragms 198a and 199a to which the heads are secured and by means of which the valve element is mounted at its ends in the end chambers. The end chamber 199 at the outer side of the diaphragm 199a is in communication with the high pressure line 104. The end chamber 198 at the outer side of the diaphragm 198a is in communication with the pilot line 87. Between the valve seats there are radial ports 205 in communication at one end with the middle chamber 203 and at their other ends with an annular passage 206 formed in the core. The annular passage 206 is in turn in communication with the passages 122 and 124. The diaphragm 199a contains ports 19% through which the pressure fluid from the high pressure line is free to flow from the end chamber 199 into the intermediate chamber 203 when the valve head 202 is open. The stem 204 has an axial passage 208 which extends from substantially midway between the opposite ends of the spindle 204 through the valve head 200 and provides communication between the intermediate chamber 203 and the end chamber 198 in both the open and closed positions of the valve. The portion of the end chamber 198 inwardly of the diaphragm 198a contains an axial port 232 which is in communication with an annular passage 234 formed in the core 103 and this in turn is in communication with an exhaust passage 164 open to the atmosphere.

The low pressure air line 110 is under pressure at all times and is arranged to pass through a valve unit 170, to be described, which is in communication with a passageway 125 in the block 102 which leads to a passageway 126 formed in the upper end 128 of the support bracket 56. The passageway 126 is provided with a nipple 130 which connects the flexible conduit 48 to passageway 46 in the stem 36 and to the air nozzle 42 forming a part of the filling head unit 16. The low pressure air line 110 also communicates with a preconvoluted rolling diaphragm 132 housed in an extended portion 134 of the block 102 and which is arranged to be actuated by the back pressure in the low pressure air line when the outlet 58 of the air noule 42 is blocked by the liquid when it reaches a predetermined height in the container. The diaphragm 132 carries a valve member 136 arranged to cooperate with a jet member 138 which is in communication with the high pressure air line 104. The jet member 138 forms part of a pneumatic high pressure control unit indicated generally at 140 which is formed in a second extension 142 ofthe block 102.

The pneumatic control 140 embodies fluid conductor means comprising a chamber 144 which communicates with the high pressure air line 104 through a restricted throat portion 146 arranged to offer a substantial resistance to the flow of air therethrough, and the jet member 138, also in communication with the chamber 144, is provided with a small discharge orifice 148. In operation, the jet member 138 may be adjusted to space the discharge orifice a predetermined distance from the valve member 136 of the diaphragm. and when the back pressure in the low pressure air line effected by blocking of the air nozzle 42 causes the diaphragm to move the valve member 136 toward the jet 138 a minute distance to reduce the discharge of air from the jet 138, a substantial rise in residual pressure occurs in the chamber 144. The chamber 144 also communicates with a chamber 150 formed in a block 151 supported on the extension 142, the chamber 150 having a resilient upper wall or rolling diaphragm 152 which carries a piston 153 and an adjustable spring loaded stem 154 arranged to be elevated when the pressure in the chamber 144 is increased. The stem 154 carries an arm 156 provided with a pin 158 which cooperates with a normally closed air escape orifice 160 formed in a jet 162 in communication with the pilot line 87.

Thus, in operation, when the diaphragm 132 is actuated in response to back pressure in the low pressure air line when a predetermined filling height is reached, the pressure in he pneumatic control is increased to raise the pin 158 from the air escape orifice 160, thus bleeding air from the pilot line 87 to reduce the pressure therein and causing the pilot valve 120 to be spring closed. Closing of the valve 120 cuts off the supply of high pressure air to the passageways 122, 124 permitting the piston 62 to be spring returned to its inoperative position, thus permitting the liquid control valve 38 to close to cut off the flow of liquid into the container. Closing of the pilot valve 120 to cut off the high pressure air also opens the lines 122, 124 to an atmospheric exhaust port 164 to effect rapid discharge of the air in the cylinder 60 and rapid closing thereof.

As further illustrated in FIGS. 5 and 11, provision is also made in the present pneumatically operated control unit for clearing the low pressure air nozzle 42 of any material which may be accumulated therein during the filling operation by directing a momentary surge of high pressure air through the nozzle at the end of the filling cycle and prior to starting a succeeding filling cycle. As shown in FIG. 5, in general, this is accomplished by means of a normally closed three-way trip valve indicated generally at 166 which is arranged to be opened by a stationary cam 168 during the operation of the machine. Opening of the valve 166 admits air from the high pressure line 104 to a line 169 which leads to a three-way normally closed valve unit 170 arranged to cut off the flow of low pressure air from line 110 through the valve 170 at this point and to admit a momentary surge of high pressure air from line 104 through the valve 170 and through the passageways 125, 126 to the low pressure air nozzle 42 to clear the same.

From the description thus far, it will be seen that successive containers 14 supported on their platforms 12 are elevated to extend the nozzles 18 into the containers in operative filling position, and elevation of a container into filling position operates to close the tire valve 88 to seal the pilot line 87 in readiness to actuate the control unit 52 to start the filling operation during rotation of the containers with their respective control units.

As illustrated in FIG. 2, the cam 118 for actuating the valve 116 is arranged in the path of a roller 172 carried by an arm 174 pivotally mounted at 175 in a bracket 176 attached to the block 102 as better shown in FIG. 9. An extension 178 from the arm 174 is arranged to depress a spring pressed plunger 180 forming a part of the valve 116 as shown in FIGS. 5 and'9. The valve 116 includes a conical spring pressed normally closed valve member 182 carried by a flexible disc having openings therein. The valve 116 also includes a similar valve member 184 carried by a flexible disc and which is normally open as shown. The valve members 182, 184 are connected by a stem 186, and intermediate the valve members is an annular passageway 188 in communication with the chamber of the air exhaust valve 88, as shown in FIGS. 9 and 10, through passageways 190, 192, 194 when the no-bottle no-fill tire valve is open. The pilot line 87 is also in communication with the passageway 192. The high pressure air from line 104 is under pressure at all times and enters through passageway 196 to the area adjacent the seated valve member 182. Thus, in operation, when the plunger 180 is depressed by the cam 118, the valve members are shifted to permit high pressure air to enter the annular passageway 188 through the central passageway and then through connecting radial passageways as shown. In the event that no container is present, the tire valve will remain open so that the momentary pulse of air effected by the cam will be exhausted through the port 92 to prevent energizing of the pilot line 87. However, when a container is present and the same is elevated into filling position to lift the weight 96 off the button 90, the tire valve will be closed when the cam 118 depresses the plunger 180, and as a result, a momentary pulse of high pressure air will enter the pilot line 87. The pilot line is connected to the end chamber 198 of the pilot valve 120. Accordingly, when the high pressure air is supplied to the pilot line the valve element 120a will be shifted in a direction to engage the head 200 with its seat and disengage the head 202 from its seat thus to admit high pressure air from the line 104 into the central chamber 203 and through the radial ports 205 to the annular passage 206 which is in communication with the lines 122, 124 leading to the cylinder 60 to start the filling cycle. A spring 19% is desirably applied to the outer side of the head 202 to assist in closing the valve. The passageway 208 in the stem permits the high pressure air to flow from the center chamber 203 into the end chamber 198 at the outer side of the diaphragm 198a to thereby hold the valve element in its open position.

When the liquid in the container reaches a predetermined height, such as to cut off the escape of low pressure air from the outlet 58, the back pressure built up in the low pressure line 110 enters a chamber 210 in back of the diaphragm 132 to reduce the gap and consequently impede the escape of air between the valve member 136 and the jet member 138. It will be observed that the low pressure air supply is provided with a relatively small inlet tube 212 comprising a Venturi tube, the end of which extends beyond the inlet 211 to the chamber 210, as shown in FIG. 8, so that in practice the air entering the line 110 will not be initially directed to the diaphragm chamber to give a false signal. On the other hand, when back pressure is developed in the line 110, the Venturi tube prevents the low pressure air from being absorbed into the supply and causes the increase in pressure to be directed to the diaphragm chamber 210. As previously described, movement of the valve member 136 toward the jet 138 causes an increase in pressure in the pneumatic unit 140 to lift the pin 158 off the air escape orifice 160 to exhaust the air in the pilot line 87. In practice, the jet 138 may be adjusted relative to the valve member 136 to obtain a predetermined increase in pressure when the diaphragm 132 is moved a distance sufficient to elevate the spring pressed stem I54 and to exhaust the pilot line 87 when a predetermined filling height is reached. As illustrated in FIG. 5, a spring 214 interposed between a shoulder 216 of the stem 154 and a collar 218 slidingly mounted on the stem may be adjusted by an adjusting cylinder 220 threadedly engaged with the block or housing 151. The

cap 222 of the cylinder engages a ball 224 set in a hollow slide rod 226 in which the upper end of the stem is received, the lower end of the rod 226 engaging the collar 218. A check nut 228 is provided to hold the cylinder in its adjusted position.

As a result, in practice each individual unit may be easily and quickly adjusted so that the pressure exerted by the spring 214 may be variedwhereby it will be overcome by a relatively small increase in the pressure built up in the chamber 150 in a manner such that a uniform filling height may be maintained in each unit. In other words, the jet member 138 may be initially adjusted to provide a predetermined uniform gap between the jet'and the valve 136 which provides a predetermined pressure in each control unit 140, as determined by a test gauge inserted into a normally closed adapter 230 as shown in FIG. 5. Thereafter, the spring pressure on the stem 154 may be individually adjusted so that any small increase in pressure in the control unit 140 above the initial setting will overcome the spring 214 to lift the pin 158 and bleed the pilot line 87.

Immediately upon exhausting the pilot line 87, the valve 120 is shifted by its spring to close off the high pressure air and to open the central chamber 203 to the atmosphere through the exhaust opening 164. As shown in FIGS. 6 and 7, the air in the cylinderpressure line 122, 124 may exhaust into the annular passageway 206 and through radial passageways 205 into the central chamber 203. The air then passes by the open valve member 200 and through a communicating passageway 232 into an annular passageway 234 which communicates with the exhaust opening 164. In this manner, the cylinder 60 is quickly evacuated to effect rapid spring closing of the liquid control valve 38 when a predetermined filling height is reached in the container. It will be observed that the chamber 198 of the pilot line 87 is also exhausted at this time through the small passageway 208 formed in the stem 204, the air passing into the central chamber 203 and out through the exhaust opening 164 as described. In the embodiment of the invention illustrated in FIG. 5, the piston 62 of the cylinder is provided with a spring 236 which returns the piston to its retracted position when the line 122, 124 is exhausted. As shown in FIG. 3, the valve stem 36 is also provided with a spring 49 to effect retraction of the valve 38 to cut off the flow of liquid into the container. However, in practice, it was found that the piston spring 236 may be eliminated in some instances, and in such cases, retraction of the stem 36 by the spring 49 is sufficient to also return the piston 62 to its retracted position since the stem is in contact with the lower end of the piston as shown. v

From the above description it will be seen that the individual control units 52 associated with each filling head may be easily and quickly adjusted to obtain a uniform filling height in successive containers by merely adjusting the tension of the spring 214. Another important feature of the presentinvention resides in the provision of a pressure regulating valve 238 (FIG. 1) in the high pressure air line 240 leading from the source of high pressure air which maybe adjusted to change the filling height in all of the containers simultaneously. As above described, the residual pressure in the control unit 140 is initially set to provide a uniform initial pressure in the chamber 144 of each unit. This chamber pressure is proportional to the initial regulated pressure in the high pressure supply line 240 leading to the high pressure lines 104 in each control unit 52. This chamber pressure is set by adjustment of the jet member 138 so that a slight increase in pressure in the chamber 144 in response to movement of the diaphragm valve 136 will overcome the force of the spring 214 to elevate the spring pressed stem 154 to exhaust the pilot line and close the liquid control valve 38. It was found in practice that by varying the pressure of the high pressure air in the supply line 240 by adjustment of the regulating valve 238, the pressure in the chamber 144 of the control unit 140 will likewise be changed proportionately in each control unit. Thus, if the main line pressure is reduced, the pressure in the chamber 144 will be reduced proportionately so that the diaphragm valve 136 will have to be moved closer to the jet 138 to effect an increase in pressure in the chamber 144 sufficient to elevate the pin 158 and exhaust the pilot line. In other words, the back pressure in the low pressure line caused by blocking off the outlet 58 will be gradually increased over a small interval of time after initial blocking to a point where the valve 136 will be moved closer to the jet 138 to effect such increase in pressure in the chamber 144 during which time the liquid will still be flowing into the container to obtain a higher filling height than that previously obtained with a different main line pressure. In practice it was found that the filling height could be varied as much as one-half inch in each container simultaneously by varying the pressure in the main supply line 240 by means of the pressure regulating valve 238.

As illustrated in FIG. 1, the main supply line 240 leads to a fitting 242 mounted on and arranged to permit rotation of an upstanding inlet pipe 244 in communication with a central high pressure air chamber 245 of an air distributing manifold 246 from which the high pressure air conduits 108 extend. The low pressure air supply lines 114 lead to the chamber 248 of a central low pressure manifold 250. Air to the low pressure chamber 248 is supplied from the high pressure chamber 245 through a pressure regulator 252 supported on the rotary disc 50 and which is arranged to reduce the pressure of the air supplied to the low pressure chamber. As shown, a pipe 254 leads from the chamber 245 to the regulator, and a pipe 256 leads from the regulator to the chamber 248.

Referring againto FIG. 5 for a more detailed description of the provision for clearing the pressure sensing nozzle 42 after each filling operation, it will be seen that the trip valve unit 166 is similar to but not exactly the same in structure and mode of operation as the trip valve unit 116 and is provided with a normally closed valve member 260 and a normally open valve member 262 connected by a stem 264. High pressure air is directed from the line 104 through a passageway 266 to a chamber in back of the normally spring closed valve 260. When the valve unit 166 is shifted by its cam 168, the valve member 262 is closed and the valve member 260 is opened to admit air past the valve 260 into a chamber intermediate the two valve members and through radial openings to an annular chamber 268 in communication with the line 169. The line 169 leads to a chamber 270 in back of a valve member 272 forming a part of the valve unit 170. The valve member 272 is connected by a stem 274 to a normally closed valve member 275 which is movable in a chamber 276 connected by a passageway 278 to the high pressure air line 104.

As illustrated in FIGS. and 9, during the filling operation the low pressure air from line 110 passes into an annular chamber 300 formed in the valve unit 170 and through a connecting passageway 302 and past the normally open valve member 272 into a central chamber 304 intermediate the valve members 272, 275. The low pressure air in the chamber 304 then passes through radial openings 306 to a second annular chamber 308 formed in the valve unit 170. The passageway 125, 126 leading to the pressure sensing nozzle 42 is in communication with the annular chamber 308 as shown. Thus, in operation, the low pressure air may pass through the valve unit 170 during the filling operation. However, when the valve unit 166 is shifted by the cam 168 after the filling operation is completed, high pressure air from the line 169 enters the chamber 270 to shift the valve members 272, 275 to the right to close off the entrance of low pressure air past valve member 272 and to open valve member 275, thus permitting high pressure air from chamber 276 to pass around the valve member 275 into the intermediate chamber 304 and through the radial passageways 306 to the annular passageway 308 in communi cation with the passageways 125, 126 leading to the low pressure air sensing nozzle 42, thus effecting clearance of any accumulated material therein by a blast of high pressure air. it will be noted that the valve member 272 is closed when the valve member 275 is opened so that no high pressure air is directed into the low pressure line 110 which might otherwise provide a false signal to the diaphragm 132. It will be understood that the nozzle clearing operation comprises merely a momentary blast of air and that the valve unit 170 immediately returns to its normal position to direct low pressure air to the sensing nozzle. As shown in FIG. 5, when the threeway cam operated valve 166 returns to its normal position with the valve member 260 closed and the valve member 262 opened, the line 169 and chamber 270 is vented through the open valve member 262, then through openings in the diaphragm 261 supporting the valve member 262, then through openings in the flange 263 of the retainer 265, then through the clearance opening in the cover 267 and finally through a slotted portion 269 of the cover to the atmosphere. The valve 170 is thus permitted to shift to the left by virtue of the spring in the chamber 276, 278. It will also be noted that each trip valve unit 116 and 166 has a relatively small movement to seat and unseat their respective opposed valve members. Hence, the button 180 is spring pressed outwardly so that when the valve is actuated by its cam, the button 180 is permitted an ample overthrow by virtue of the spring.

As illustrated in detail in FIG. 17, the cams 118 and 168 are mounted in the path of their respective rollers 172 of the control units 52, the cam 168 for effecting clearing of the sensing nozzle 42 preceding the cam 118 for initiating the filling operation so that the sensing nozzle 42 is cleared and the material discharged directly into its bottle prior to start of the filling operation. As herein shown, each cam 118, 168 is similarly supported with the nozzle clearing cam 168 mounted above and preceding the cam 118 for starting the filling cycle. One end of each cam is pivotally mounted at 310 in a horizontal bar 312 extending from a bar 314 which is adjustably supported in a vertical bar 316 clamped to a supporting post 318.

The post 318 is supported by a bracket 315 attached to the machine frame. The other end of each cam is connected by a link 320 to the piston stem 322 of an air cylinder 324. During operation of the machine, air is supplied to the cylinder 324 by a supply pipe 326 which is connected to a regulated source of compressed air. Thus, each cam is extended and maintained in thepath of its respective rollers 172 by a cushion of air in the cylinders, movement of the cams toward the control units being limited by adjustable screws 328 carried by the bar 312.

In practice, the air to the cylinders 324 is controlled by a solenoid valve 330 in the supply pipe 326, the solenoid valve being connected in the motor circuit, not shown, in a manner such that the valve 330 (FIG. 1) is opened when the motor is started and closed when the motor is stopped. When the air is shut oit by the solenoid valve 330, the air entrapped in the supply line 326 serves to maintain the cams in their operative extended position as controlled by an exhaust needle valve 332 carried by the solenoid valve 330 and which permits the entrapped air to slowly bleed from the supply line. The advantage of this expedient is that when the motor is stopped and the air to the cylinders is cut off, the rotary filling heads with their control units continue to rotate for a short distance until they coast to a stop. Thus, the cams are maintained in operative position during this relatively short interval in order to effect nozzle clearing of the units which pass the cams and also to initiate the filling operation of such units. On the other hand, if the cylinders 324 were immediately exhausted, the cams 118, 168 would retract immediately with an uncontrolled exhaust and those filling units which passed the cams would not be energized to clear their sensing nozzles 42 or to initiate a filling operation resulting in an empty container in the line when the machine is again started. Another advantage ofa controlled exhaust is that if a filling head came to rest with its roller 172 against its cam 118 to open the valve 116, high pressure air would continue to signal initiation of a filling cycle unless the cam was subsequently retracted by means of the controlled exhaust valve 332 provided with the solenoid valve 330.

In a modified form of the filling machine, it is sometimes preferred not to clear the sensing nozzle 42 into a container about to be filled. in such cases, the position of the cam 168 for effecting a momentary blast of air through the nozzle is mounted in a position between the intake and discharge spiders where the circular path is free of containers, as shown in FIG. 187 When the nozzle 42 is cleared by a blast of air in this position, the cleared material may be collected in a removable drip pan 334 supported beneath the filling head units. The cam for triggering the clearing operation in its modified position is designated by the numeral 168a, and the manner of supporting the cam is similar to that shown in FIG. 17, the parts being identified by the same numbers with the addition of the letter 0 except that the vertical bar 316a is adjustably attached to a bracket 335 secured to a stationary rail 337 attached to the machine frame.

The advantage of effecting the nozzle clearing operation in a position other than when the nozzle is inserted into a container is that, in practice, a container may not be present at the clearing station because of a void in the line of supply of containers, and when the nozzle clearing operation is performed without a container present on the elevating platform 12, the cleared material will be discharged onto the platform. It is also possible that when a relatively small neck bottle is being filled, a discharge of high pressure air into the bottle with the cleared material may pressurize the bottle to an extent such that the pressurized air will not have entirely escaped out of the mouth of the container by the time the closely spaced cam 118 effects initiation of a filling cycle. As a result, such pressure could back up through the low pressure nozzle 42 and into the line to give a false signal to the diaphragm 132 to thus prematurely terminate the filling cycle.

In practice, various types of filling nozzles 16 may be used which are adapted for different types of materials being run. The filling nozzle 16 shown in FlG. 3, wherein the liquid control valve 38 is disposed at the end of the nozzle may be used for most free-flowing liquids and is designed to prevent dripping of the nozzle after the filling operation is completed. Referring now to FIG. 12, the filling head therein shown is provided with a liquid control valve 38a which comprises a conical valve formed on the stem 36a and having an O-ring 338 arranged to seat against a conical surface 340 formed in the nozzle block 22a below the liquid inlet pipe 23a. In this embodiment the lower end of the air nozzle 42a is also pro vided with a tubular valve member 38 telescopically fitted into the lower end of the liquid nozzle 180 which is provided with liquid escape openings 59a exposed when the valve is extended, as shown, and closed by the nozzle 18a when the valve is retracted. The remaining portions of the filling head shown in FIG. 12 are similar to those shown in FIG. 3 and are designated by the same numerals with the addition of a letter a. This type of nozzle may be used with advantage in cases where the material being run is not subject to dripping from the nozzle.

The filling head shown in FIG. 13 is similar to that shown in FIG. 3 except that the mounting for the low pressure air nozzle 4217 which carries the valve member 38b is secured to the stem 36b during assembly in a manner such as to present the liquid discharge openings 5912 directed toward the wider sides of a container which is oval in cross section. In some instances, depending on the product and the shape of the container, it may be preferred to direct the liquid toward the narrower walls. The upper end of the nozzle 42b is carried by an adapter 441) which has an extension 342 having a press fit into the lower end of the stem 36!), In operation, the stem 36b and air nozzle 42b do not rotate relative to the nozzle block 22b. ln assembly, the nozzle 42b is pressed into the stem in a position to direct the liquid discharge openings laterally toward the wider walls of the container and is maintained in this position by a check nut 344 threadedly engaged with the exterior of the stem and in locking engagement with the end of the adapter 44b. When filling into a cylindrical container, directional discharge openings are not required since the container walls are equally distant from the liquid nozzle. However, when a bottle, oval is cross section is run, nondirectional discharge outlets might cause the liquid to flow against a closely spaced wall, resulting in excessive turbulence of the liquid which might interfere with the filling operation. Thus, the expedient of directing the discharge outlets 5% toward the more distantly spaced walls avoids such turbulence. As above stated, in some instances it may be desirable to direct the liquid toward the narrower walls.

FIG. 14 illustrates another modified form of filling head wherein the air nozzle 420 is disposed outside the liquid nozzle 18c leaving the inside diameter of the liquid nozzle free ol any obstructions. This type of filling head is particularly adapted for use when running relatively thick or viscous fluids. As herein shown, the filling nozzle I80 is entirely open without an air nozzle extending therethrough whereby to provide a maximum cross-sectional inside diameter area for the viscous material to flow thereby providing a maximum flow per unit of time to substantially reduce the filling time for the viscous material. Also, the valve member 380 for cooperation with the valve seat 400 is not extended into the nozzle I80. As shown in FIG. 14, the air nozzle 42c is carried by a clamp member 346 adjustably secured to one of the nozzle guide slide rods 80. The upper end of the air nozzle 420 is curved and extended laterally and is connected to a flexible conduit 480, the other end of which is connected to the nipple 130 leading to the low pressure air line 110 of the control unit 52.

In operation, when the container is elevated into seating engagement with the nozzle guide 76, the air nozzle 420 is extended into the container to a predetermined height in the container, and during further elevation of the container with its platform 12, the air nozzle 42c and the nozzle guide 76 move together to present the container into operative filling position to the nozzle 18c. In this elevated filling position the end of the air nozzle 420 extends a short distance below the end of the filling nozzle in the usual manner to sense the height of the liquid when it reaches the end of the air nozzle to discontinue the filling operation by closing the inlet valve 38c. In this type of filling head there is no upward movement of the air nozzle at the end of the filling operation. In other words, the end of the air nozzle remains in the same position relative to the end of the liquid nozzle during the filling operation and after the filling operation is completed. At the end of the filling cycle, the elevating platform is lowered with its container, at which time the nozzle guide 76 together with the air nozzle 42c is also lowered until it comes to rest in its fully lowered position whereupon the container is further lowered away from the air nozzle to permit the container to be transferred to the discharge conveyor.

FIG. 15 illustrates an embodiment of a filling head wherein both the liquid filling nozzle 18d and the low pressure air sensing nozzle 42d are connected to move together. This type of filling head is also particularly adapted for running viscous or semiviscous materials. It will be seen that when using the type of filling head shown in FIGS. 12 or 13 wherein the lower valve member 38 or 38b is telescopically extended during the filling operation, any material collected on the outer surface of the valve during the filling operation will be wiped off by the end of the liquid nozzle when the valve is retracted. With a nonviscous material, such wiping does not present any problem. However, when a viscous material is used, the material wiped off may collect around the end of the liquid nozzle in a large ring which might interfere with the filling operation. In the embodiment shown in FIG. 15, this problem is avoided by moving both nozzles together without any wiping action. As illustrated, the nozzle 18d is fitted into the end of the valve stem 36d and is retained therein by a check nut 356. The low pressure air nozzle 42d extends through the upper end of, the nozzle 18d into a chamber which communicates with the air passageway 46d formed in the stem 36d. When the valve 38d is opened, the liquid entering the chamber 240' may pass through openings 358 in the wall of the nozzle 18d and into a relatively small liquid nozzle 360. The air nozzle and liquid nozzle may be joined together by welding or brazing and are extended through a sleeve 362 within the nozzle 18d as shown. The nozzle 18d is guided by a bushing 364 retained at the bottom of the extension 27d of block 22d by a flanged nut 366 as illustrated. The air nozzle 42d extends a short distance below the end of the liquid nozzle 360, and in operation, when the valve 38 d is opened, both nozzles arelowered simultaneously. Thereafter, when the liquid reaches a height such as to block the air from the outlet 58d, the pneumatically operated unit 52 is actuated to permit the valve 38d to be spring closed. Thus, the end of the liquid nozzle 360 is disposed above the material in the container during the filling operation and is never immersed into the material so that the outer surface thereof is free of any accumulation of viscous material. Another advantage of using the structure shown in FIG. 15 is that when a relatively narrow mouthed container is to be filled, the two small nozzles arranged side-by-side providing two contiguous tubes, when fitted into the relatively narrow circular mouth of the container, provides more space in the mouth on each side of the tubes for air in the bottle to escape when displaced by the liquid during the filling operation. Such air escape space in the present embodiment is proportionately greater for the same diameter container mouth than the design wherein the air nozzle is disposed within the liquid nozzle. It will be appreciated that failure of the air to escape rapidly from the mouth might buildup the pressure in the container during the filling operation to give a premature signal to the diaphragm I32 of the control unit which would discontinue the filling operation before a predetermined height is reached.

Another modification of the filling head nozzle structure is shown in FIG. 16 wherein the low pressure air nozzle 42e is also mounted outside the liquid nozzle 182 but in a manner such as to be capable of movement vertically relative to the liquid nozzle. As herein shown, the liquid nozzle l8e is secured in the lower end of the nozzle block extension 27e.

Clamped to the fixed liquid nozzle l8e is a bracket 368 having an extension 370. which supports an air cylinder 372. The low pressure air nozzle 42e is slidingly extended through the bracket 368 in contiguous engagement with the liquid nozzle l8e, as shown, and a second bracket 374 clamped to the air nozzle 422 is connected to the piston rod 376 of the cylinder 372. The upper end of the air nozzle 42e is connected by a flexible conduit 48:? to the nipple 130 in the upper end 128 of the support bracket 56 and which communicates with the low pressure passageway 126, 125 of the control unit 52. The air cylinder 372 is connected by a flexible conduit 378 to a nipple 380 in communication with the passageway 124 of the control unit 52 which leads to the cylinder 60. In operation, when the.

pilot valve 120 is opened to direct high pressure air through passageway 122, 124 to the cylinder 60, the air is simultaneously directed through the conduit 378 to the cylinder 372 to extend its piston rod and lower the air nozzle 42e below the end of the filling nozzle. Subsequently, when the opening in the end of the air nozzle 422 is blocked by the liquid reaching a predetermined height to automatically effect shifting of the valve 120, the air in the cylinder 60 is exhausted, whereupon the valve 382 is spring closed, and likewise the air in the cylinder 372 is also exhausted, whereupon the piston rod 376 is spring returned to elevate the air noule 42e to its initial position. As described in connection with the structure shown in FIG. 14, one advantage of employing the structure shown in FIG. 16 is that it eliminates any obstruction within the liquid nozzle to provide a greater cross-sectional area for viscous materials to flow through the nozzle, thus affording a relatively faster filling time.

In accordance with another feature of the invention, the present pneumatic control unit 52 is adapted to purge the containers with an inert gas, such as nitrogen, prior to and during the filling operation. In practice, the control unit 52a may be similar to the control unit 52 except that low pressure nitrogen is substituted for the low pressure air in line 110, and the lower portion of the control unit is modified, as shown in FIGS. 19 and 20, to provide a momentary surge of high pressure nitrogen for the nozzle clearing operation from a line 382 through the valve unit 1700 instead ofa surge of high pressure air as provided in the unit shown in FIG. 5.

As diagrammatically indicated in FIG. 21, the low pressure air line 110a is connected to a source of low pressure nitrogen at the inlet 112a so that in operation nitrogen is arranged to flow continuously through the valve 170a and into the container during the filling operation in the manner previously described in connection with the structure shown in FIG. 5. In operation, when the trip valve unit 166a is actuated to shift the control valve 170a, the low pressure nitrogen line 110a is cut off and the valve unit 1700 is opened to the high pressure nitrogen line 382. Thus, the empty container is provided with a momentary surge of high pressure nitrogen to clear the sensing nozzle 42 of any material accumulated therein and to also provide an initial purging of the container with the inert gas. Thereafter, the valve unit 170a is automatically returned to its normal position, as previously described, to deliver low pressure nitrogen from line 1100 through the valve 170a to the sensing nozzle 42. Immediately after the noule clearing operation, the trip valve unit 116a is actuated to initiate the filling operation during which time the low pressure nitrogen continues to flow through the nozzle 42 into the container. Thus, the containers are purged with an inert gas prior to and during the filling operation to reduce to a minimum any air in the container which might be detrimental to the product being run.

As illustrated in detail in FIGS. 19 and 20 and diagrammatically in FIG. 21, it will be seen that in the modified structure of control unit 52a the high pressure air in line 1040 communicates with a chamber 278a and passageway 196a to admit the air to the pilot line 87a when the trip valve unit 1160 is actuated in the same manner as in the structure shown and described in connection with FIG. 5. Also, the high pressure air in line 104a. is in communication with the pilot valve 120a to admit air to the cylinder line 122a and 124a to the cylinder 60a, the same as previously described. High pressure air is also in communication with the air jet 1380. Similarly, high pressure air is in communication with the trip valve 166a to admit high pressure air to the line 169a leading to the chamber 270a for shifting the valve unit 170a. However, as shown in FIGS. 19 and 20, the high pressure air is sealed off from the righthand end of the valve unit 170a by an adapter 384 having an O-ring 386. Instead, the chamber 388 defined by the end of the adapter 384 and the valve member 275a is in communication with passageways 390, 391' connected to the inlet 392 of I the high pressure nitrogen conduit 382. Thus, in operation,

the machine wherein provision is made for supply high pressure air; low pressure nitrogen; and high pressure nitrogen from central supply chambers'and through radially extended conduits connected to successive pneumatically operated control units 52a. As therein shown, high pressure air is supplied by a pipe 400 to a cylindrical bearing member 402 arranged to permit rotation of the central air manifolds with the machine. The high pressure air passes through a central pipe 404 directly into the high pressure air chamber 406 from which the flexible conduits 408 extend for connection to their individual control units 52a. High pressure nitrogen is supplied by a pipe 410 connected to a source of supply thereof and which is in communication with a hollow chamber formed in the bearing member 402 which is in communication with an intermediate manifold 412. The manifold 412 is connected by a pipe 416 to the chamber 418 of the high pressure nitrogen manifold 420 from which flexible conduits 422 extend for connection to their respective control units 52a. Low pressure nitrogen is supplied to the chamber 424 of manifold 426 from a pressure regulator, not shown, similar to that shown in FIG. 1, by a conduit 428, the pressure regulator being connected to the high pressure nitrogen chamber 418 by a conduit 430. Flexible conduits 432 extended radially from the low pressure chamber 424 are connected to their respective control units 52a. The center'section also includes the liquid manifold 434 whose chamber 436 receives the liquid from the supply in the manner shown in FIG. 1 and which is provided with radially extended pipes 438 connected to the nozzle blocks 22 of their respective filling heads 16.

In the operation of the machine, the containers 14 are elevated on their platforms 12 into filling relationship to their respective nozzles at which time the normally open exhaust valve 88 is closed to cut off the exhaust of the pilot line through the ports 92. Thereafter, the filling operation is initiated by triggering the valve unit 116, and the filling cycle is tenninated when the liquid in the container blocks the opening 58 of the sensing nozzle 42. In the event that the liquid in the supply is depleted before it reaches the predetermined filling height, or failure of the container to receive sufficient material to reach the low pressure outlet during its continuous movement in a circular path, or in the event of failure of the low pressure air supply, no signal will be received by the control unit to exhaust the pilot line 87 so that the valve unit 120 will remain in its operative filling position. However, as each filling unit approaches the container discharge end of its cycle, the elevator 12 lowers its container, and simultaneously therewith, the nozzle guide 76 with its supporting structure is also lowered, thus effecting opening of the tire valve by lowering of the weight 96 onto the button of the exhaust valve 88. Thus, the pilot line is exhausted through the ports 92 to effect shifting of the valve unit in readiness for a succeeding cycle of operation. 

1. In a container-filling machine, a filling assembly comprising a nozzle for delivering material to the mouth of the container to fill the same, a sensing device having an end adjacent the nozzle operable by impingement of the material in the container therewith to produce a signal, a filling valve for controlling flow of material through the nozzle to the container, a fluid pressure system connected to a source of fluid at superatmospheric pressure in which control is achieved by varying the level of the superatmospheric pressure in the system, comprising fluid conductor means connected in said system to which said superatmospheric pressure is supplied, pneumatically operable means connected to said fluid conductor means, said pneumatically operable means being constantly operated upon by said superatmospheric pressure in said fluid conductor means, and including a pressure operable valve embodying a diaphragmsupported pressure operable valve element movable between first and second positions to effect opening and closing of the filling valve, said diaphragm-supported valve element being adapted to be held in each of said positions by fluid pressure, means embodied in said pressure operable valve operable to hold said valve element at said first position once it is moved to said first position so long as said holding pressure is maintained unchanged, means for moving said valve element to said second position in response to a change in said holding pressure effected by an increase in pressure in said fluid conductor means, said fluid conductor means containing an outlet through which said superatmospheric pressure fluid flows at a predetermined rate such as to maintain an inoperative superatmospheric pressure in said fluid conductor means, and means operable in response to said signal to modify the flow of said superatmospheric pressure fluid through said outlet opening in a manner to change the pressure in said fluid conductor means from an inoperative to an operative pressure.
 2. Apparatus according to claim 1, comprising adjustable means operable to vary the response of the pneumatically operable means to the change of pressure in said fluid conductor means.
 3. Apparatus according to claim 1, wherein the fluid conductor means comprises a chamber and the outlet is an orifice through which said fluid under pressure flows at a predetermined rate, and the means operative in response to a signal from the sensing means to change the flow of fluid through said orifice is a diaphragm supported adjacent the orifice for movement relative thereto in response to said signal from said sensing means.
 4. Apparatus according to claim 3, wherein the means operative in response to a signal from the sensing means is a diaphragm supported adjacent the orifice, the sensing means comprises an air conducting sensing tube supported with one end adjacent the nozzle and the other end adjacent the diaphragm, and wherein there is means supporting the diaphragm in confronting relation to the orifice with its center substantially in alignment therewith, and means for adjusting the initial distance between the diaphragm and the orifice.
 5. Apparatus accordiNg to claim 1, comprising a normally open exhaust valve in said fluid pressure system which maintains the superatmospheric pressure in said system below operating level, and means operable by positioning a container in filling position to close said normally open exhaust valve.
 6. Apparatus according to claim 5, comprising means for moving a container to a filling position and removing it therefrom following filling, said means being operable successively to close the normally open exhaust valve and thereafter open the exhaust valve.
 7. Container-filling apparatus comprising a plurality of filling assemblies according to claim 1, comprising means connecting the fluid pressure system of each assembly to a common source of regulated superatmospheric fluid pressure such that the initial pressure in each fluid conductor system is proportional to said regulated pressure, and means for varying said regulated pressure and consequently the pressure in each of said fluid pressure systems simultaneously.
 8. Apparatus according to claim 1, wherein an exhaust valve embodied in said pneumatically operable means is operable by a change in pressure in the fluid conductor means to change the holding pressure supplied to said pneumatically operable valve.
 9. Apparatus according to claim 1, wherein said diaphragm supported, pressure operable valve element is adapted to be held in a normally closed position, and there is means embodied in said pressure operable valve operable by delivery of a pulse of superatmospheric pressure thereto to move said valve element to its open position.
 10. Apparatus according to claim 1, wherein the pneumatically operable means includes a cylinder containing a piston and means connecting the piston to said filling valve, and wherein said pressure operable valve supplies fluid pressure to said cylinder to effect opening of said filling valve.
 11. Apparatus according to claim 10, wherein there is spring means operable when said pressure operable valve is returned to its closed position to return said filling valve to its closed position.
 12. Apparatus according to claim 10, wherein said pressure operable valve contains an exhaust opening normally closed when said pressure operable valve is in its open position and open when said pressure operable valve is in its closed position, and means connecting said exhaust opening to said cylinder to induce rapid venting of the cylinder and hence retraction of the piston and closing of said filling valve.
 13. Apparatus according to claim 1, wherein there is means including a conductor tube for supplying low pressure air continuously to a sensing tube in said sensing device and a second pressure operable valve interposed in said conductor tube and connected into said fluid pressure system, movable from a first position in which it permits free flow of the low pressure air supplied to the sensing tube from the conductor tube and blocks pressure from the fluid pressure system to a second position in which it blocks flow of low pressure air from said conductor tube to the sensing tube and permits flow of pressure from said fluid pressure system through the sensing tube, and means for shifting said second pressure operable valve, momentarily from said first position to said second position following completion of a filling operation and then returning it to its first position to inject a charge of superatmospheric pressure from the fluid pressure system through said sensing tube so as to clear the same.
 14. Filling apparatus according to claim 1, wherein there is means including a conductor tube for supplying a gaseous medium continuously to a sensing tube in said sensing device and wherein said pneumatically operable means includes a second conductor tube for supplying a gaseous medium at a higher pressure than that supplied to said sensing tube, a second pressure operable valve interposed in said first conductor tube and connected to said second conductor tube, said second pressure operable valve being movable from a first position in which it permits free flow of the lower pressure gaseous medium through the sensing tube and blocks access of the higher pressure gaseous medium thereto, to a second position in which it blocks the lower pressure gaseous medium from the sensing tube and permits the higher pressure gaseous medium to flow therethrough, and for shifting said second pressure operable valve from said first position to said second position and back again following the conclusion of each filling operation.
 15. In a container-filling machine, a filling assembly comprising a nozzle for delivering material to the mouth of the container to fill the same, a sensing device having an end adjacent the nozzle operable by impingement of the material in the container therewith to produce a signal, a filling valve for controlling the flow of material through the nozzle to the container, a fluid pressure system connected to a source of fluid at superatmospheric pressure in which control is achieved by varying the level of the superatmospheric pressure in the system, comprising fluid conductor means connected in said system to which said superatmospheric pressure is supplied, pneumatically operable means connected to said fluid conductor means, said pneumatically operable means being constantly operated upon by said superatmospheric pressure in said fluid conductor means, a diaphragm exposed to the superatmospheric pressure in said fluid conductor means, an exhaust valve in said fluid pressure system, said diaphragm being operably connected to said exhaust valve, spring means opposing movement of the diaphragm, means for adjusting the yield at a predetermined operative pressure, said fluid conductor means containing an outlet through which said superatmospheric pressure fluid flows at a predetermined rate such as to maintain an inoperative superatmospheric pressure in said fluid conductor means, and means operable in response to said signal to modify the flow of said superatmospheric pressure fluid through said outlet opening in a manner to change the pressure to said fluid conductor means from an inoperative to an operative pressure. 